Feeding mechanism for sewing machines



June 30, 1925. 1 1,543,945 J. R. MOFFATT- v FEEDING MECHANISM FOR SEWINGMACHINES FiledApril 19, 1921 3 Sheets-Sheet 1 a; a 1 j.

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v J. R. MOFFATT FEEDING MECHANISM FOR SEWING MACHINES Filed April 191921 3 Sheets-Sheet 2 June 30, 1925..

' J. R. MOFFATT FEEDING MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet 5File d April 19. 1921 Patented June 30, 1925.

. UNITED STAT PATENT OFFICE.

JAMES R. MOFFATT, or CHICAGO, ILLINoIs, AssIeNoa'ro UNIoN SPECIALMACHINE COMPANY, or CHICAGO, ILLINoIs, A CORPORATION or ILLINoIs.

FEEDING MECHANISM FOR SEWING MACHINES.

Application filed Apri1'19, 1921. Serial No. 462,571.

To all whom it may concern:

Be it known that I, JAMES R. luOFFATT, a citizen of the United States,residing at Chicago, in the county of Gook, State of Illinois, haveinvented certain new and useful Improvements in Feeding Mechanisms forSewing Machines, of which the following is a description, referencebeing had to the accompanying drawing and to the figures of referencemarked thereon.

The invention relates to new and useful improvements in feedingmechanisms for sewing machines, and more particularly to a feedingmechanism which includes a feed dog mounted beneath the work supportandoperating through, slots in the work sup:.

port for engaging and feeding the material.

v An object of the invention is to provide a feed .dog supporting andoperating means feed dog supporting, means beneath the work support;

which permits the feed dog to be shifted laterally, orin a direction atright angles to the line of feed, to center the fabric engaging portionsthereof in the slots through which they operate.

A further object of the invention is to provide a feeding mechanismwherein the means for supporting and operating the feed dog is soconstructed as to permit the working position of the fabric engagingportions of'the feed dog to be centered in the feed slots through whichthey operate; or, in other words, to be shifted in the line of feed.

These and other objects will in part be obvious and will in part behereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of theinvention Figure 1 is a view in top plan of a portion of a sewingmachine having my improvement embodied therein, and with a part of thework support broken away to show the Figure 2 is a View partly invertical. section and partly in elevation from the left hand end of themachine; I

Figure '3 is a View partly in section and partly in rear elevation ofthe same;

Figure 4- is a longitudinal sectional view on the line 44 of Fig. 1;

Figure 5 is an enlarged view, partly in section, of the crank pin discon the main shaft;

' length.

Figure 6 is a perspective View, with parts separated, showing feedrocker, feed bar and feed dog; and i Figure 7 is a section on line 77 ofFigure 6.

The invention is directed broadly to a feeding mechanism of the typewherein a feed dog is mounted beneath the work support and is providedwith fabric engaging sections operating through slots in the worksupport or-throat plate forming a part of -the work support. This feeddog is carried by a feed bar which is pivotally connected to a feedrocker. The feed'rocker is provided with spaced supporting lugs in whichis mounted a bar or shaft to which the feed bar is fixedly connected.This bar or shaft is secured from endwise movements in the lugs byadjustable collars. By loosening the collars or loosening the connectionbetween the feed bar and the bar or shaft mounted in the lugs, theentire feed bar may be moved laterally, or in a direction at rightangles tothe line of feed, for ositioning the fabric engaging sectionsof the feed dog centrally of the slots in the throat plate.

The feed rocker is operated by an arm connected to a crank on the mainshaft. On said crank is an eccentric sleeve which is clamped in the endof the arm and by adjusting this sleeve the working position of thefabric engaging sections of the feed dog may be shifted back and forthand thus centered relative to the longitudinal length of the slots inthe throat plate.

Referring more in detail to the drawings, my improved feeding mechanismis shown as applied to a sewing machine having a bed plate 1, on whichis mounted a. work support 2. The work support 2 is provided with athroat plate 3 which is secured to the work support by suitable screwsfr-4:, and, in fact, becomes a part of the work support. This throatplate is provided with. needle'holes 5-5 and with feed slots 6, 7 and 8.Mounted beneath the work support is a feed dog 9, which in turn isprovlded with fabric engaging sections 10, 11- and 12. Thesefabricengaging sections respec-- tively extend through the slots 6, 7and8, and engage the fabric resting on the work support and throat plateto feed it a stitch I This feed dog 9 is provided with a shank," 13,which is slotted at 14. The shank 13 fits in a recess in a feed bar15,and a -screw 16 passing through the slot 14 rigidly clamps the shankof the feed dogin the. recess in the feed bar. Attached to the feed bar15 is'a plate 17.- The feed bar carries a hardened plate 18, which restson an eccentric 19, carried by the main shaft 20. The plate .17 engagesthe underface of this eccentric the shaft 23 there is a collar 26, whichis secured to the'shaft 23 by a set screw 27, which is not spotted, sothat said collar 26 may be shifted endwise of the shaft 23. At theopposite end of the shaft 23 there is a similar collar 28, whichissecured to the shaft by a set screw 29. These collars bear against theouter faces respectively of the lugs 2525.

Said feed rocker 21 is also provided with upwardly extending lugs 3030,in which is mounted a shaft 31, so that said shaft/may freely turn insaid lugs 30. The feed bar 15 is provided with integral sleeves 32-32,

which are mounted on this shaft 31 and these sleeves are secured to theshaft by means 'of set screws 33, so that thefeed bar is fixed to theshaft 31. On the right hand end 0f.the shaft 31 there is a collar34'which is secured to the shaft by. a set screw 35 which is notspotted, so that said collar may be shifted endwise of the shaft 31. Atthe opposite end of the shaft 3lthere 'is a similar collar 36, securedthereto by a set screw 37 These collars bear against the outer facesrespectivelyof the lugs 3030. I 5

Attention is particularly called to the fact that the distancebetweenthe outer faces of the lugs 2222 is considerably less than thedistance between the inner faces of the bearing lugs. 2525, so that byloosening the collars 26 and 28, the shaft 23 may be shifted Qendwise inthe lugs 2525 and thus the whole feed rocker shifted endwise ortransversely of the direction of its rocking movemerit and the directionof movement of the feed dog by the sewing machine. Itwillb'e readilyseen that this endwise shifting of the:

feed rocker results in a lateral shifting of the feed bar and throughthis lateral shifting of the feed bar the fabric engaging sections 10,11 and 12 of the feed dog may be centered in the, slots 6, 7 and 8, inwhich they work. This is a great advantage as it eliminates a 7 .closemilling operation between the lugs feed bar or 2222 and 25-25, or thebending of the the filing away of the shank of the feed dog, or in someother way the re.-

" shaping or reforming of the metal to penter shifted laterally and thusthe fabric engaging sections of the feed dog properly centered in theslots in the work support.

The feed rocker is oscillated to impart back and forth movements to thefeed dog.

by means of an integral arm 38. This arm 38 is split at 39, as isclearly shown in Figure 6, and is provided with a cylindrical recess 40,into which the split end leads. Located in this cylindrical recess 40 isa split sleeve 41, which has :rflanged head 42 notched, as indicated at43. Said sleeve is I I split, as indicated at 44, and has a cylindricalopening 45 which is eccentrically disposed relative to the center of.the sleeve and the center of the recess 40. The split end'of the arm'38carries a set screw 46 by means of which the sleeve 41 may be fixedlyclamped in the outer end. of the arm 38. By loosening the. screw, itwill be apparent that the sleev'emay be readily adjusted through the'aid of the notches in the flange carried thereby. Clamped in saidcylindrical opening 45 by the screw 46 is a pivot pin 47, the center ofwhich is, of course, eccentric to the center of the sleeve 41. Looselyengaging the pivot'pin 47. is one end of al'ink v48 and said link .atits other end engages a crank pin 49, carried by a plate 50,-which ismounted to slide back and forth in a slot 51 in a disc 52 secured to theend of the mainshaft 20. A screw 53 is threaded through said plate 50and is held from endwise movement by a 'bracket piece 54, lying betweencollars carried by the screw, and said bracketv piece is secured tothedisc 52 by meansof screws 55. By turning thescrew 53 the crank pin 49 isshifted toward and from the center of the shaft for varying the strokeofthe feed dog. When the pivot *pin 47: is shifted through the adjustingof the sleeve 41, the arm 38 will be'swung toward or from the crank pin49, a'nd'the swinging of the arm 38 will change slightly the workingposition of the fabric engaging sections of the feed 7 dog. If,therefore, when the parts are assembled,.it is found that the feed dogis working too close to the front end of the slots 6, 7 and 8,.then thispin 4''( is shifted so as. to -move,the working position rearwardlychine is set up, the fabric engaging sections of the feed dog may becentered in the feed slots in the work support, so that they will moveback and forth without binding against the side walls of the slot; and,on the other hand, the stroke of the feed dog may be shifted so that thecenter of the longitudinal stroke of the feed dog will be centered withthe longitudinal length of the slots.

It is obvious that minor changes in the details of construction and thearrangement of parts may be made without departing from the spirit ofthe invention, as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A feeding mechanism for sewing machines including in combination awork support having feed slots therein, a feed dog mounted beneath thework support and having fabric engaging sections extending through saidslots, means for raising and lowering the feed dog, means for moving thefeed dog back and forth, said last named means including adjustabledevices for varying the working position of the fabric engaging sectionsof the feed dog without changing the length of the feed stroke,

whereby the same may be centered longi tudinally of the respective slotsin which said sections operate.

2. A feeding mechanism for sewing machines including in combination a,work support having feed slots therein, a feed dog having fabricengaging sections workin in said slots, a feed bar supporting said feeddog, means for raising and lowering the feed bar, a feed rocker formoving the feed bar back and forth, means for oscillating said rocker,devices connecting the feed bar to the-feed rocker, and devices forsupporting said feed rocker, one of said devices being manuallyadjustable, whereby the feed bar may be shifted laterally for centeringthe fabric engaging sections thereof in their respective slots, andmeans whereby the working position of the fabric engaging sections ofthe feed dog may be shifted longitudinally of the feed .slots forcentering said sections longitudinally of the respective slots in whichthey operate and without varying the length of the feed stroke.

3. A feeding mechanism for sewing machines including in combination, awork support having feed slots therein, a feed dog having fabricengaging sections working in said slots, a feed bar carrying said feeddog, means for raising and lowering the feed bar, a feed rocker, an'armintegral with said feed rocker, a pin carried ,by the outer end of saidarm, a link connected to said pin for oscillating the arm for moving thefeed dog back and forth, and means whereby said pin may be shifted insaid arm forvarying the working position of the fabric engaging sectionsof the feed dog in their respective slots. I

4. A feeding mechanism for sewing ma chines including in combination, awork support having feed slots therein, a feed dog having fabricengaging sections working in said slots, a feed bar carrying said feeddog, means for raising and lowering the feed bar, a feed rocker, an armintegral with said feed rocker, a sleeve adjustably mounted in the outerend of said arm, a pin eccentrically carried thereby, means for engagingsaid pin for oscillating the arm, and means for clampingsaid sleeve inan adjusted position.

5. A feeding mechanism'for sewing inachines including in combination, awork support having feed slots therein, a feed dog 30 having fabricengaging sections working in said slots, a feed bar carrying said feeddog, means for raising and lowering the feed bar, a feed rocker, an armintegral with said feed rocker, a split sleeve mounted in the outer endof said arm, the outer end of said arm being split' and having aclamping screw for clamping said sleeve, said sleeve having an openingeccentrically located therein, a pin mounted in said open- 5 ing, and alink connected to said pin for oscillating said arm. I

i 6. A feeding mechanism for sewing machines including in combination, awork support having feed slots formed therein, a 9

feed dog havlng fabricv engaging sections working in said slots, a.ndmeans for supporting and actuating said feed dog including deviceswhereby the fabric engaging sections may be shifted laterally in theirre- 1 spectiveslots for centering the same relative to the slots andwhereby the working position of said fabric engaging sections may beshifted longitudinally of their respective slots for centering the samelongitudinally of the slots.

7. A feeding mechanism for sewing machines including in combination, awork support having feed slots therein, a feed dog having Iabricengaging sections working-in saidslots, a feed bar carrying said feeddog, means for raising and lowering the feed bar, a feed rocker, an armintegral with said feed rocker, a split sleeve mounted in the outer endof said arm, a pin in said sleeve, a link connected to said pin foroscillating said arm on the feed rocker, and a clamping screw for theouter end of said arm for clamping the pin in the split sleeveand'clampingthe sleevejjii-n said split arm.

8.-'A.feeding mechanism for sewing machines including in combination, afeed dog, a feed bar, a feed rocker to'which said bar is connected, abed plate having spaced lugs, a shaft mounted in said lugs, collars onthe 7 of a bed plate, a feed rocker mounted therec outer ends of saidshaft and engaging respectively the outer faces of said lugs to preventendwise movement of said shaft-and permitting said shaft to be adjustedendwise and held in adjusted positions, said feed rocker having sleevesthrough which said shaft extends, said sleeves being fixed to the shaftand having their outer faces a less distance apart than the distancebetween the inner faces of the lugs carrying said shaft. 7

9. In a sewing machine, the combination 011, means for oscillating said'feed rocker, a

" feed dog, a feed bar carrying said dog, said feedbar having spacedsleeves, said feed rocker having spaced sleeves, a shaft passing throughsaid sleeves for connecting the feed bar to the feed rocker, saidsleeves on the feed bar being fixed to the shaft, and collars.adjustably mounted on the outer ends of said shaft and bearing againstthe outer faces of the sleeves on the feed rocker, the distance betweenthe outer faces of the sleeves on the feed bar being less than thedistance between the inner faces of the sleeves on the feed rocker,whereby the shaft may be adjusted endwise.

In testimony whereof, I afiix my signa ture. I

JAMES R, MOFFATT.

